Power-brake



(No Model.) Y 2 Sheets-Sheet 1.

L. P. LAWRENCE.

POWER BRAKE.

No. 432,948. Patented July 22, 1890.

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2 Sheets-Sheet 2.

(No Model.)

L. P. LAWRENCE.

POWER BRAKE.

Patented July 22,1890.'

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NITED STATES LOUIS P. LAVRENOE, OF PASSAIC, NEV JERSEY.

POWER-BRAKE.

SPECIFICATION forming part of Letters Patent No. 432,948, dated July 22, 1890. Application tiled April 24, 1890. Serial No. 349,311. (No model.)

To @ZZ whom it may concern:

Beit known that I. Lo'UIs P. LAWRENCE, of Passaic, in the county of Passaic and State of New Jersey, a citizen of the United States, have invented certain new and useful Improvements in Power-Brakes, of which the following is a specification.

This invention relates to improvements in power-brakes for railway-cars; and the object of my invention is to provide a new and irnproved power-brake apparatus by means of which the brake-shoes, which are of the ordinary construction and arranged and hung in the usual manner, can be applied very easily and rapidly.

In the accompanying drawings, Figure l is a longitudinal horizontal sectional view of my improved power-brake for railway-cars, the parts being in positions they have when the brake is not applied. Fig. 2 is a vertical longitudinal sectional view, parts being shown in elevation, and the piston having the position it has when the brake is not applied. Fig. 3 is a vertical transverse sectional view, on the line 3 3, Fig. 2, showing the slotted hanger for the guide-bar. Fig. 4c is a transverse sectional view on the line 4 l, Fig. 2.

Similar letters of reference indicate corresponding parts.

The cylinder A isI provided on its top with a cylindrical projection B, having a collar O That part of the projection B above the collar fits snugly in the circular aperture D in the bottoni of a circular track D, suitably bolted to the under side of the car-bottom E. A circular plate F is bolted to the top of the cylindrical projection B, and extending over the edges of the same rests upon the bottom plate of the circular track D, thereby suspending the cylinder A in such a manner that it can turn with the center of the projection B as its axis-that is to say, it is swiveled on the under side of the car-bottom.

Within the cylinder A the piston G is arranged, which is of such diameter that its edges are quite close to the inner walls of the cylinder. O11 said piston the circular packing-plate H, of leather or other suitable material, is placed, which is of such diameterthat its edges extend beyond the edges of the piston and rest against the inner walls of the cylinder. On the packing-plate Il the packing-plate 112, of rubber, is placed, which also extends beyond the edges of the piston and rests against the inner walls of the cylinder. On the packing-plate H a metal disk J is placed, which is provided with a circular ridge J 3. The disk J is pressed against the packing-plate H2, and the ridge J 3 forced into the rubber packing-plate H2 by a pin or key J driven into the neck G of the piston, which neck serves to receive one end of the pistonrod I, the pin J also serving for holding the piston-rod in said neck G.

The piston-rod I is guided in an aperture in the head K of the cylinder A, and the opposite head Kzis cast integral with the cylinl der and is provided with a neck K3 for coupling the air-exhaust pipe. The head K is provided with a recessed bracket L, in which.

one end of a guide-bar M is secured, the opposite end passing through a transverse slot N in the hanger N, bolted to the under side of the car-bottom E, as shown in Figs. 2 and 3. That end of the piston-rod I opposite the one fastened to the piston is bolted to a flat box O, having side slots O. rlhe box is provided with an upwardly-projecting hanger P, in the top of which a roller P is mounted on a transverse pin P2, said roller resting and running upon the upper edge of the guidebar M. In that end of the box O nearest the cylinder A two links Q are pivoted to swing in the plane of the box, the opposite ends of said planes being pivoted in recesses R in the cam toggle-heads R2 of links R. Said cani toggle-heads R2 have rounded edges, which rest against each other, and those ends of the links R opposite the ones provided with the cani toggle-heads are pivotally connected with the shorter ends of the horizontally-swinging levers S, pivoted in the hangers T, bolted to and projecting downward from the under side of the car-betteln E. The longer ends of the levers S are connected with the brake-pull rods U. A check-block V is provided with an aperture through which'the guide-bar M passes, and'is also provided with a screw V', by means of which said check- IOO block can be locked in any desired position on said guide-bar M in advance of the hanger P.

The operation is as follows: When the air is exhausted from one end of the cylinder A, the pressure of the atmosphere forces the piston G in the direction of the arrow fr', whereby the piston-rod I and the box O are pulled in a like direction. The links Q pull the links R in the same direction, whereby the shorter ends of the levers S are moved from each other, as indicated by the arrows, and the brake-rods U are pulled in a direction toward each other, as is also indicated by the arrows. The pull-rods U are thus subjected to a tensile strain, and the brake-shoes are applied. The cam toggle-heads R2 have their rounded edges shaped in such a manner that at the beginning of the stroke the brakerods are pulled up very rapidly to take up lost motion, and then the rods are pulled toward each other at a decreased speed', so as not to strain the parts unduly.

If the cylinder A were fixed, any irregularity in the hanging of the brake-shoes would cause the shoes on one truck to be applied with more force than the shoes on the other truck. To avoid this, the cylinder has been swiveled, so that when the shoes of the wheels on one truck have been applied with sufficient force the entire cylinder can swing sufliciently to apply the shoes on another truck with the same force. By this arrangementl at all times obtain an equal pressure of the brake-shoes on all the wheels. As thecylinder swings to adjust itself, the guid e-bar M, the piston-rod, and the box O swing with it, the guide-rod M being guided at its free end in the slot N of the hanger N. In case the brake-shoes and wheeltires wear off the stroke of the piston must be adjusted accordingly, and this is accomplished by setting the check-block V'in different position. lf the check-block V is set nearer the head K of the cylinder, the piston G, on making its return-stroke when the brakes are released, cannot pass to the extreme left-hand end of the cylinder, but is checked a greater or less distance from the same. It thus follows that the stroke in the direction of the arrow x-that is, when the brakes are applied-cannot be as great as when the piston is permitted to pass to the extreme left-hand end of the cylinder. As the brake-shoes and wheel-tires wear off, the block V must be adjusted to permit the piston to make a greater stroke accordingly as .the distance between the adjacent surface of the wheel-tires and brake-shoes increases.

The guide-bar M is provided with a graduated scale, as shown in Fig. 2, to facilitate adjusting the block V according to the wear of the shoes and tires.

Having thus described my invention, I

claim as new and desire to secure by Letters Patent l 1. In a brake, the combination, with a cylinder swiveled to the car, of a piston in the cylinder, a guide-bar attached to said cylinder, a guide for the free end of said guidebar, a box on the piston-rod connected with the piston, which box is suspended from and adapted to run on said guide-bar, and brakeoperating levers connected with said box, substantially as set forth. Y

2. In a brake, the combination, with a cylinder swiveled to the car, of a piston inthe same, a guide-bar connected with said cylinder, a hanger fori'supportingV the free end of said guide-bar, a piston-rod projecting from the piston, a box on the end of the pistonrod, a hanger for suspending said box from and guiding it on the guide-bar, a check-piece on said guide-bar, and brake-operating levers connected with said box, substantially as set forth.

3. The combination, with a swiveled cylinder, of a guide-bar connected with said cylinder, a piston and piston-rod, and means for suspending the free end of the piston-rod from said guide-bar and guiding it on the same, substantially as set forth.

4. The combination, with a cylinder, of a piston and piston-rod, of a box on the end of said piston-rod, links pivoted to said box, spread levers having toggle-cam heads within the box, links pivoted to the box and to the toggle-cam heads, and brake-levers connected with the levers having the toggle-cam heads, substantially as set forth.

5. .In a power-brake, the combination, with a cylinder, piston, and piston-rod, of a box on the end of the piston-rod, toggle-levers having toggle-cam heads within the box, links connecting the toggle-cam heads with the box, pivoted levers connected with those ends of the toggle-levers opposite the ones having the toggle-cam heads, and pull-rods connected with the opposite ends of said pivoted levers,

substantially as set forth.

6. The combination, with a cylinder, of a piston, a packing-plate of iiexible material resting against said piston, a disk resting against said packing-plate, and a pin for IOO locking said disk in place and thereby holding the packing-plate in place, substantially as set forth.

7. The combination, with a cylinder, of a piston, a leather packing-plate resting against the piston, a rubber packing-plate resting against the leather packing-plate, a disk resting against the rubber packing-plate, and means for locking said disk in place, substantially as set forth.

8. The combination, with a cylinder, of a piston, packing-plates resting against the piston, a diskresting against the packingplates and provided on the face resting against the packing with a rib that is forced into the packing, and means for locking said disk in place, substantially as set forth.

9. The combination, with a cylinder and,

piston, of a guide-bar provided with a gradcar to swing in :t plane parallel with the car- 1o mated seele, a check-block on said guide-bar, bottom, substantially as set forth. a box mounted to slide on the guide-bar and In testimony that I claim the foregoing as operated from the piston, and brake-operatmy invention I have signed my name in pres- 5 ing' levers in said box, substantially as set ence of two subscribing Witnesses.

fortha LOUIS P. LAWRENCE.

l0. A power-brake comprising a cylinder, Witnesses: piston, and brake mechanism, said cylinder JULIUS JENSEN,

being mounted pivotally to the bottom of the IVM. F. GASTON. 

